CN111818857A

CN111818857A - Medical fixing device

Info

Publication number: CN111818857A
Application number: CN201980017477.1A
Authority: CN
Inventors: 奥利·喀拉嫩
Original assignee: Medtentia International Ltd Oy
Current assignee: Medtentia International Ltd Oy
Priority date: 2018-01-05
Filing date: 2019-01-04
Publication date: 2020-10-23
Also published as: EP3735186A1; US20210052384A1; EP3735186A4; CA3087446A1; WO2019135028A1

Abstract

A medical fixation device (100) for securing or coupling an object (400A, 400B) into tissue (20) having a proximal portion (100A) and a distal portion (100B). It further comprises a helical structure (107), wherein the helical structure comprises a thread or ridge (104) having a lead (105) between the proximal and distal portions. The helical structure comprises a first portion (101/103) and a second portion (102) immediately adjacent to the first portion (101). The thread of the helical structure advantageously extends through the first portion (101) and the second portion (102) and a property, such as pitch and/or lead, of the thread varies along the longitudinal axis (106) of the helical structure such that the property of the thread has a first value in the first portion (101) and a second value in the second portion (102) to provide different compressive forces to objects and/or tissues introduced into said first and second portions of the helical structure, and wherein the first value is different from the second value.

Description

Medical fixing device

Technical Field

The present invention relates to a medical fixation device for securing an object to tissue. In particular, the present invention relates to a medical fixation device adapted for fixing a cardiac implant (e.g. an annuloplasty ring) into the annulus of a heart valve (e.g. a mitral or tricuspid valve), said annulus being made of valve tissue and comprising an annulus and a plurality of leaflets. The principles of the present invention may be applied to catheter-operated or cannula-operated medical fixation devices, as well as to open-heart surgery medical fixation devices. Furthermore, the principles of the present invention may also be applied to the fixation of other objects, such as tissue, implants or subcutaneous skin grafts, etc. In addition, the invention can also be used for fixing artificial objects, such as, for example, heart valves or implants.

Background

Fig. 1A shows a portion of a heart 12, a mitral valve 18, and a left ventricle 14. The mitral valve is surrounded at its border by a ring 20. The valve has two cusps or

leaflets

22, 24. Each of these tips or

leaflets

22, 24 is connected to a respective papillary muscle 27, 29 via their respective connecting

chordae tendineae

26, 28. In a normal healthy individual, the free edges of the opposing leaflets will close the valve by coaptation. However, for some individuals, the closure is incomplete, which results in regurgitation, also known as valve insufficiency, i.e. blood regurgitating into the left atrium making the heart less effective and potentially serious consequences for the patient. Fig. 1B shows the mitral valve 18 in which the

leaflets

22, 24 are not properly closed. This typically occurs when the ring 20 expands. One surgical procedure to correct this situation is to remove a portion of the leaflets 24 and stitch the cut edges together with one another. The program will pull the ring 20 back to a more normal position. But changes the strength of the leaflet 24. Similar problems of less effective heart function may occur if one or both leaflets are perforated to the extent that blood flows to the left atrium, despite proper closure of the leaflets.

In certain cases of deteriorated cardiac function, such as in degenerative valve disease, the leaflets do not present a solid surface. The leaflets may also rupture, most often at the edges of the leaflets, resulting in incomplete coaptation. Accordingly, cardiac devices and methods have been developed for repairing one or more leaflets of a heart valve, or other associated anatomical structures, such as chordae tendineae attached to the ventricular side of the leaflet.

Fig. 2A and 2B show a prior art cardiac implant device and method for repairing one or more leaflets of a heart valve, as described in applicant's previous european patent (EP 1853199B 1), wherein the device 40 comprises a first loop-shaped support 42 and a second loop-shaped support 44, which are connected to each other by a connecting part 48 so as to form a coil shape. As described in more detail in this patent, the coil shape of the device is advantageous during insertion because the device 40 can then be rotated into position. One of the supports 44 may be open (e.g., C-shaped or D-shaped or any other anatomical shape) such that the support 44 presents one end to guide the movement of the support 44 as it is rotated into position. The position of the

brackets

42, 44 is fixed by fasteners 56 which are inserted and fixed by hand or by a small screwdriver.

It has been found that prior art cardiac implant devices, such as those described above, work very well, but there are still some drawbacks involved in securing the cardiac device to the annulus of the heart valve. Cardiac devices, such as other objects like cardiac implants or tissue or skin grafts, are usually sewn manually by conventional needles and yarns or by using different kinds of machine screws.

One of the main problems with fixation is to securely fix the object, but at the same time not to cause significant stress or cracking to the tissue to which the object is fixed. For example, if the object to be secured must be in a compressed state after securing, the suture or screw must be securely tightened, which is a very challenging task so that the tissue to which the object is secured is not over-compressed and thus does not cause damage to the tissue. This may occur, for example, when a dual ring cardiac implant device 40 having a first ring support 42 and a second ring support 44 must be firmly pressed against each other so as to tightly secure tissue 20 between first ring support 42 and second ring support 44. In some cases it may even be necessary to fix the object such that it is in a depressurized state after fixation, which is a very challenging or even impossible task to accomplish with the known prior art solutions.

Disclosure of Invention

It is an object of the present invention to mitigate and eliminate problems related to the known prior art. In particular, it is an object of the present invention to provide a medical fastening device for fastening an object to tissue, such that the object can be fastened and compressed tightly and firmly to the tissue, or decompressed such that the tissue is not subjected to the same compressive forces as the object. The object may be, for example, an implant (such as a cardiac implant), or other tissue or skin graft.

The object of the invention is achieved by the features of the independent claims.

The invention relates to a medical fixation device according to claim 1.

According to one embodiment of the present invention, a medical fixation device or fixation device for securing or coupling an object into tissue includes a helical structure and proximal and distal portions. The helical structure includes threads or is disposed in the form of threads, for example, after the helical structure is introduced into tissue. The interior of the helical structure is advantageously a hollow or empty space for receiving portions of the object and/or tissue. The threads have a lead and pitch or other properties between the proximal and distal portions. In addition, the helical structure includes a first portion, for example in a proximal or distal portion of the medical fixture, and a second portion adjacent the first portion.

The property of the thread is advantageously the pitch or lead of the thread in the direction of the longitudinal axis of the helical body structure. The lead is the distance along the longitudinal axis of the helical structure that is covered by one full rotation (360 °) of the medical fixture. The pitch is the distance from the crest or ridge of one thread to the crest or ridge of the next thread, which is the same as the lead when the thread of the medical fixture has one start point, but is different from the lead if there are two or more start points. Generally, lead is equal to the pitch multiplied by the number of starts.

Likewise, the nature of the thread may also be the helix angle (opening angle) or the diameter or pitch of the thread (and thus the material of the helical structure) or the diameter of the helical structure. However, these are merely examples, and the present invention is not limited to only those examples. For example, when the diameter of the lead or spiral structure changes, the area of the lead or spiral structure also changes, and thus the pressure change or pressure caused by the structure may spread differently, which may be advantageous in some applications. For example, the diameter of the helical structure may be larger in the second portion than in the first portion or the third portion, and the helical structure may then force the objects and/or tissue at the second portion to expand more. With this embodiment, the pressure can also be spread over a larger area at the second portion. Alternatively, the diameter of the helical structure may be smaller in the second portion than in the first portion or the third portion, whereupon the helical structure may force the objects and/or tissue at the second portion to contract less. In this embodiment, the pressure may be spread over a larger area at the first portion and/or in the third portion.

According to an advantageous embodiment, the thread of the spiral structure is arranged to extend through the first and second portions. In addition, a property of the thread (such as, for example, the pitch or lead) is arranged to vary along the longitudinal axis of the helical structure such that the property of the thread has a first value in a first portion and a second value in a second portion. Thereby, different compressive or decompression forces may be provided to the objects and/or tissues introduced into the first and second portions of the helical structure. The first value is advantageously different from the second value, and the properties of the thread may vary in a linear or non-linear manner in the direction of the longitudinal axis of the medical fixture, depending on the application in which the medical fixture is used.

According to one embodiment, the medical fastening device may further comprise at least two helical structures having a common longitudinal axis. In this embodiment, both helical structures include their own threads with a lead between the proximal and distal portions of the helical structures. Each helical structure also includes a first portion, for example in the proximal portion, and a second portion adjacent the first portion. The threads of the helical structure also extend through the first and second portions. The properties of the threads advantageously vary along the helical structure such that the properties of the threads in both helical structures have a first value in a first portion and a second value in a second portion, thereby providing different compressive or decompression forces to objects and/or tissues introduced into said first and second portions of the helical structure, similar to in an embodiment with one helical structure. However, when two or more spiral structures are used, the compressive or decompression force introduced into the object and/or tissue may be stronger and, in addition, the object may also be better grasped and secured in the transverse direction (perpendicular to the longitudinal axis of the spiral structure).

According to one embodiment, the helical body structure may further comprise a third portion immediately adjacent to the second portion. The third portion may be arranged, for example, at a distal portion of the spiral structure such that the second portion is located between the first portion and the third portion. The threads of the helical structure advantageously extend along the helical structure through the first, second and third portions. In addition, properties of the thread (such as, for example, pitch and lead) are arranged to vary along the helical structure such that the properties of the thread have a first value in a first portion, a second value in a second portion, and a third value in a third portion. Depending on the application, the first value is different from the second value, again the first and third values may also be the same or different from each other.

According to an advantageous embodiment, the pitch and/or lead of the thread is shorter (or has a greater density) in the second section than in the first section and/or the third section. Thus, the object may be arranged in a compressed state after fixation, which may be useful in certain situations, for example when the object has to be compressed more than the tissue surrounding it, or when the object is another tissue that is tougher than the tissue to which the tougher tissue is fixed. For example, first and second loop-shaped

supports

42, 44 of a dual loop cardiac implant device 40 (shown in fig. 2A) may be securely pressed against each other in such a manner that tissue 20 will be tightly secured between first and second loop-shaped

supports

42, 44.

According to another advantageous embodiment, the pitch and/or lead of the thread is longer (or has a lower density) in the second section than in the first section and/or the third section. Thus, the object may be arranged in a reduced pressure state after fixation, which may be useful in certain situations, for example when the object has to be compressed differently than the tissue surrounding it, or when the object is another tissue being softer than the tissue to which said softer tissue is fixed. For example, the first and second annular supports 42, 44 of the dual ring cardiac implant device 40 (shown in fig. 2A) may not be compressed or decompressed away from each other in such a manner that the tissue 20 will not be compressed or compressed more between the first and second annular supports 42, 44 than in a steady state (no external force is applied to the annular supports).

According to one embodiment, the starting point of the helical structure in the distal end (such as the third part) may have a larger lead and/or pitch than the second part, which advantageously forces the thread of the second part to "open" or stretch at least a little in the longitudinal direction of the helical structure together with the object when the helical structure is introduced during fixation with the object, whereupon the thread of the second part will compress back to the initial state when the distal end or the third part has passed the object. In this way, the object may be compressed by the second portion of the helical structure. According to another embodiment, the starting point of the spiral structure in the distal end (such as the third section) may have a smaller lead and/or pitch than the second section, whereupon the effect is reversed and the result is that the threads of the second section will "open" or unwind back to the initial state (decompression).

It is noted that the object may be a cardiac implant, such as for example an annuloplasty ring, but may also be a tissue, implant or skin graft, whereupon the tissue, implant or skin graft may also cause the second portion to "open" or to stretch or behave the opposite, such as described above.

As may be noted in this document, the nature of the thread may have different forms, and it may be implemented or realized in a variety of ways, such as a thread may have, for example, a certain pitch and/or lead before introduction to an object and/or tissue. According to one embodiment, the helical structure may further comprise a shape memory material (such as nitinol including nickel and titanium) that is resiliently biased to beneficially change the property value of the thread after introduction into the tissue. For example, due to the shape memory material in the first, second and/or third portions, the properties of the threads in these portions may be changed such that, for example, after introduction of the portions into the tissue, a certain compressive or reduced pressure force may be applied to the object and/or tissue in the portion of the spiral structure in question. According to one example, the spiral structure may include a shape memory material that is resiliently biased to form a thread having particular properties after introduction into tissue.

Further, according to one embodiment, the distal portion of the helical structure may include a non-traumatic tip that expands tissue fibers as tissue is introduced and thereby facilitates both introduction and penetration of the distal portion into the tissue, as well as grasping or twisting around an object. In addition, the proximal portion of the helical structure advantageously comprises a grip portion via which the medical fixture can be rotated about its longitudinal axis by the introduction device. The gripping portion may be embodied as a specific protrusion or protruding portion or a curved portion, such as a 90 ° angle portion.

The medical fixation device also advantageously includes a securing member for engaging and securing the medical fixation device with the object in a direction of the longitudinal axis of the helical structure and in a transverse direction perpendicular to the longitudinal axis. In this way, the medical fixation device prevents the object from sliding out of the hollow interior space, or in other words, prevents the medical fixation device from rotating on itself and opening, but also prevents the medical fixation device from being over-tightened or "on" the object to be fixed such that the object will slide out and exit via the proximal portion of the medical fixation device.

According to one example, the fastening member comprises a slot or recess having an opening to receive the object into the opening. When the medical fixation device is screwed or rotated during fixation, the object will be received into the hollow interior space and until the object reaches the opening, the slot or recessed portion of the fastening member of the medical fixation device will snap over the object, thereby fastening and locking the medical fixation device to the object. Advantageously, a slot or recess having an opening is arranged at a proximal portion of the medical fixation device.

According to one example, the grip portion may serve as a stop member to prevent the medical fixation device from being secured too tightly or "flipping" over the object, and thereby preventing the object from sliding out of the hollow interior space via the end of the proximal portion of the medical fixation device. The grip portion serving as a stop member is advantageously arranged to be substantially elongated over the hollow interior space and, in addition, it is advantageously arranged to extend over the hollow interior space substantially perpendicular to the longitudinal axis. Furthermore, a grip portion serving as a stop member is advantageously arranged in the proximal portion of the medical fixation device.

Advantageously, the fastening member of the medical fixation device comprises both a slot or recess having an opening and a stop member. In this case, the opening and the stop member are arranged such that there is a distance between them in order to arrange sufficient space for the object to be fastened.

According to one embodiment, the helical body structure may further comprise a shape memory material, which is advantageously elastically biased to form the fastening member after introduction into the tissue. The shape memory material may be resiliently biased to form, inter alia, an opening and/or a gripping or stopping member when the portion of the spiral structure comprising the shape memory material is in contact with tissue.

The fastening member provides advantages such as fastening the medical fixation device to an object such that loosening or undesired rotation of the medical fixation device may be avoided. In addition, it is also possible to avoid fixing the medical fixation device too tightly, even beyond or through the object or target depth.

The present invention provides advantages over known prior art techniques, such as securing an object to tissue so that the object can be tightly and securely secured and compressed or decompressed to the tissue so that the tissue is not subjected to the same compressive or decompression forces as the object. This therefore minimizes the likelihood of tissue rupture or damage due to tight and secure fixation. In addition, the present invention also enables fixation of an object such that the object or tissue is in a reduced pressure or slightly open state after fixation.

The exemplary embodiments presented herein should not be construed as limiting the applicability of the appended claims. The verb "to comprise" is used herein as an open limitation, not to exclude the presence of unrecited features. The features recited in the dependent claims may be freely combined with each other, unless explicitly stated otherwise.

The novel features believed characteristic of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific exemplary embodiments when read in connection with the accompanying drawings.

Drawings

The invention will be described in more detail hereinafter with reference to exemplary embodiments according to the accompanying drawings, in which:

figures 1A to 1B schematically show a part of a heart and a mitral valve,

fig. 2A-2B illustrate a prior art cardiac implant device for repairing one or more leaflets of a heart valve, an

Figure 3 shows the principle of an exemplary medical fixing device for fixing an object into tissue according to an advantageous embodiment of the invention,

figures 4 to 5 show an exemplary medical fixing device with two spiral structures according to an advantageous embodiment of the invention,

fig. 6 to 7 show an exemplary medical fixing device with a fastening member according to an advantageous embodiment of the invention, an

Fig. 8-9 illustrate an exemplary medical fastening device in use, according to an advantageous embodiment of the present invention.

Detailed Description

Fig. 1A to 1B and fig. 2A to 2B have been discussed in more detail in connection with the background of the invention section above.

Fig. 3 illustrates the principle of an exemplary medical fixation device 100 for fixing or coupling objects 400A, 400B into tissue 20, comprising a helical structure 107 and a proximal portion 100A and a distal portion 100B, according to an advantageous embodiment of the invention. Fig. 4-5 illustrate an exemplary medical fastening device 100 having two spiral structures 107.

In both examples, the helical structure includes or is in the form of threads 104, wherein the interior portion surrounded by threads 104 is an empty space or cavity 114 to receive at least a portion of an object and/or tissue. In the example shown, the thread 104 has a lead 105 and a pitch p between a proximal portion and a distal portion in the direction of the longitudinal axis 106 of the helical structure 107, and likewise of course also other properties described in this document, such as the helix angle or opening angle α, the diameter t or pitch of the thread (i.e. the diameter t of the material of the helical structure) or the diameter d of the helical structure. In addition, the spiral structure comprises a first portion 101, advantageously in the proximal portion 100A of the medical fixture, and a second portion 102 adjacent to said first portion 101.

The lead 150 is the distance along the longitudinal axis 106 of the helical structure 107 that is covered by one full 360 rotation of the medical fixture. The pitch p is the distance from the crest or ridge of one thread to the crest or ridge of the next thread, which is the same as the lead 105 when the thread of the medical fixture has one start point, but is different from the lead if there are two or more start points (e.g., as is the case in fig. 4 and 5).

As can be seen in fig. 3 to 5, the threads of the spiral structure 107 are arranged to extend through the first portion 101 and the second portion 102. In addition, a property of the thread (such as lead 105 or pitch p, for example) is arranged to vary along the longitudinal axis 106 of the helical structure 107 such that the property of the thread has a first value in the first portion 101 and a second, different value in the second portion 102. Even though not shown in the figures, the diameter d of the helical structure may be larger in the second portion 102 than in the first portion 101 (or the third portion 103), so that the helical structure may force the

objects

400A, 400B and/or the tissue 20 at the second portion 102 to expand, e.g., perpendicular to the longitudinal axis 106. Alternatively, the diameter d of the helical structure may be smaller in the second portion 102 than in the first portion 101 (and/or the third portion 103), so that the helical structure may force the

objects

400A, 400B and/or the tissue 20 at the second portion 20 to substantially contract towards the longitudinal axis 106.

As can be seen in fig. 4 to 5, the medical fastening device 100 has two spiral structures 107 having a common longitudinal axis 106. In this embodiment, both helical structures include their own threads 104 having a lead 105 and a pitch p between the proximal and distal portions of the helical structures. Each helical structure 107 further comprises a first portion 101, for example in a proximal portion, and a second portion 102 immediately adjacent to said first portion 101.

Furthermore, as can be seen in fig. 3 to 5, the spiral body structure 107 may further comprise a third portion 103 immediately adjacent to the second portion 102. The third portion 103 is advantageously arranged in the distal portion 100B of the spiral body structure 107 such that the second portion 102 is located between the first portion 101 and the third portion 103. The thread 104 of the helical structure advantageously extends along the helical structure through said first, second and

third portions

101, 102, 103. In addition, the properties of the thread (such as, for example, the pitch and lead 105) are arranged to vary along the helical structure such that the properties of the thread 104 have a first value in the first portion 101, a second value in the second portion 102, and a third value in the third portion 103.

In addition, as can be seen in fig. 3-5, the lead 105 and/or pitch p of the thread 104 is shorter (or has a greater density) in the second portion 102 than in the first portion 101. Thereby, the

objects

400A, 400B may be arranged in a compressed state after being fixed. Even if not shown, the pitch p and/or lead 105 of the thread 104 may be longer (or less dense) in the second section 102 than in the first section 101, so that a decompression state after fixing the object may be achieved.

Further, the distal portion 100B of the helical structure 107 may include a tip 108 that both facilitates introduction and penetration of the distal portion into the tissue 20, as well as grasping of the

object

400A, 400B or twisting around the

object

400A, 400B. In addition, the proximal portion of the screw structure 107 may advantageously comprise a grip portion 109 via which the medical fixture 100 may be rotated about its longitudinal axis 106 by an introduction device (not shown), as can be seen in fig. 6. The grip portion 109 may be embodied as a specific protrusion or protruding portion or a curved portion, such as a 90 ° angle portion.

Fig. 6 also illustrates the principle of an exemplary medical fixation device 100 having a fastening member 112 for locking or fastening the medical fixation device 100 to an

object

400A, 400B after the

object

400A, 400B is fixed to the tissue 20. The fastening member 112 may, for example, comprise a slot 110 or recess 110 with an opening 111, which is advantageously located at the proximal portion 100A of the medical fixation device 100. In use, the

object

400A, 400B to be secured is received into the opening 111 such that the opening will at least partially surround the object. The slot 110 or recessed portion may have a spring-like feature to "snap" around an object, particularly a ring-shaped object (e.g., a cardiac implant device having the first and second ring supports 42, 44), when tightened or rotated about its longitudinal axis 106, and when a portion of the object is located "inside" the threaded helical structure 107. Additionally, the

objects

400A, 400B may also be slightly compressed by the spiral structure 107 before snapping into the slot or recess 110. The opening 111 is advantageously arranged in the proximal portion 100A of the medical fixture 100.

When the medical fixation device 100 is tightened or rotated during fixation, portions of the object will be received into the hollow interior space 114, and when the object reaches the opening 111, the slot 110 or recessed portion 110 of the fastening member 112 will snap over the object, thereby enclosing, fastening, and locking the medical fixation device 100 to the

object

400A, 400B. The slot or recess 110 may have a spring-like characteristic such that it bends when it is turned and faces the object and will return to a normal state after a portion of the object is introduced into the opening 111. In addition, as can be seen in particular in fig. 6, the width a of the jaw or mouth of the opening 111 is advantageously arranged such that it is a little smaller than the diameter or thickness d of the

objects

400A, 400B, whereupon the

objects

400A, 400B force the slot or recess 110 to bend a little so that the

objects

400A, 400B can enter the opening. Further, the extent or depth of the opening 111 must be large enough to be able to receive the

objects

400A, 400B inside.

It is noted that the grip portion 109 may also advantageously serve as a stop member 109, as can be seen at least in fig. 6 and 8-9. The gripping portion or stop member 109 may, for example, elongate over a hollow interior space 114 substantially perpendicular to the longitudinal axis 106, as can be seen in fig. 7-9, thereby preventing the medical fastening device 100 from being secured too tightly or "flipping" over an object. A grip portion or stop member 109 is also advantageously disposed in the proximal portion 100A of the medical fixation device 100.

In general, the fastening member 112 secures the medical fixture 100 to an object in a direction along the longitudinal axis 106 of the helical structure 107, and in a transverse direction 113 perpendicular to the longitudinal axis 106. In this way, the fastening member 112 prevents the

objects

400A, 400B from sliding out of the hollow interior space 114 and prevents the medical fastening device 100 from rotating and opening itself. In addition, the fastening member 112 also prevents the medical fixation device 100 from being over-fastened or "on" the object to be secured such that the object will slide out and exit via the proximal end portion 101A of the medical fixation device 100.

Fig. 8-9 illustrate an exemplary medical fixation device in use, according to an advantageous embodiment of the present invention, wherein objects 400A, 400B are secured to tissue 20 by medical fixation device 100. As can be seen in fig. 8-9, the medical fixture 100 is tightened around the

objects

400A, 400B such that portions of the objects are located inside the hollow interior space 114 of the medical fixture 100. At the same time, the grip portion or stop member 109 prevents further tightening of the medical fixture 100, and thus also prevents the

objects

400A, 400B from sliding out in the longitudinal direction 106 and away from the hollow interior space 101 of the medical fixture 100. In addition, the opening 111 (not shown in fig. 8-9) prevents the

objects

400A, 400B from sliding out in the transverse direction 113 and away from the hollow interior space 114 of the medical fixture 100.

The invention has been explained above with reference to the aforementioned embodiments and several advantages of the invention have been demonstrated. It is clear that the invention is not only restricted to these embodiments, but comprises all possible embodiments within the spirit and scope of the inventive idea and the following patent claims.

The features recited in the dependent claims may be freely combined with each other, unless explicitly stated otherwise.

Claims

1. A medical fixation device (100) for securing an object (400A, 400B) in tissue (20), wherein:

-the medical fixture (100) having a proximal portion (100A) and a distal portion (100B) comprises at least two helical structures (107) having a common longitudinal axis (106), wherein each of the helical structures comprises its own thread (104) with a lead (105) between the proximal and distal portions of the helical structure,

-each of the spiral structures comprises a first portion (101/103) and a second portion (102) immediately adjacent to the first portion (101),

wherein

-the thread of the spiral structure extends through the first and second portions (101, 102), and wherein after the spiral structure is introduced into the tissue (20), at least one property of the thread varies along the longitudinal axis (106) of the spiral structure such that the property of the thread (104) in both of the spiral structures has a first value in the first portion (101) and a second value in the second portion (102) to provide different compressive forces to the object and/or the tissue introduced into the first and second portions of the spiral structure, and wherein the first value is different from the second value.

2. The apparatus of claim 1, wherein the apparatus comprises

-a third portion (103) immediately adjacent to the second portion (102) such that the second portion (102) is between the first and third portions (101, 103), and

-the thread (104) of the spiral structure extends along the spiral structure through the first portion (101), second portion (102) and third portion (103), and wherein at least one property of the thread varies along the spiral structure after introduction of the spiral structure into the tissue (20), such that the property of the thread (104) has a first value in the first portion (101), a second value in the second portion (102) and a third value in the third portion (103), and wherein the first and/or third value is different from the second value.

3. The apparatus of claim 2, wherein the first value and the third value are the same; or wherein the first value and the third value are different from each other.

4. The device of any preceding claim, wherein the property of the thread (104) is a pitch and/or lead (105) of the thread in a direction of the longitudinal axis (106) of the helical structure (107), a helix angle or thickness of the helical structure or a diameter of the helical structure (107), or a width or depth of the thread.

5. The device of any preceding claim, wherein the pitch and/or lead of the thread (104) is shorter in the second part (102) than in the first part (101); or the pitch and/or lead of the thread (104) is longer in the second part (102) than in the first part (101).

6. The device according to any of the preceding claims, wherein the spiral body structure (107) comprises a shape memory material which is resiliently biased to change the value of the property, such as the distance between adjacent pitches and/or leads, of the threads in the first part (101) or in the second part (102) after introduction of the tissue and thereby provide a different compressive force to the object and/or tissue introduced into the first part (101) of the spiral body structure than to the object and/or tissue introduced into the second part (102).

7. The apparatus of any of the preceding claims,

wherein the distal portion (100B) of the helical body structure (107) comprises a non-traumatic tip (108) to be introduced into the tissue (20).

8. The device according to any preceding claim, wherein the proximal portion (100A) of the spiral structure (107) comprises a gripping portion (109) engaged with an introduction device and for rotating the medical fixture (100) about its longitudinal axis (106).

9. The device according to any of the preceding claims, wherein the fixation device (100) comprises fastening means (112) for engaging and fastening the medical fixation device (100) with the object (400A, 400B) in the direction of the longitudinal axis (113) of the spiral structure (107) and in a transverse direction (103) perpendicular to the longitudinal axis (106), and thereby preventing the object (400A, 400B) and the medical fixation device (100) from being separated from each other.

10. The device according to claim 9, wherein the fastening member (112) comprises a slot (110) or recess (110) having an opening (111) and arranged in the proximal portion (100A) of the medical fixation device (100) to receive the object (400A, 400B) to be fixed into the opening (111) and for locking the medical fixation device (100) to the object (400A, 400B) after the object (400A, 400B) is fixed to the tissue (20) by the medical fixation device (100).

11. The device according to any one of claims 9 to 10, wherein the fastening member (102) comprises a gripping portion serving as a stop member (109) arranged to be substantially elongated over the hollow interior space (101) of the spring-like spiral body structure (107) and thereby configured to prevent the object from slipping out of the hollow interior space via the end of the proximal portion (100A).

12. The device according to any preceding claim, wherein the spiral structure (107) comprises a shape memory material which is resiliently biased to form a fastening member (102) according to claim 9 after introduction into the tissue,

or wherein the shape memory material is resiliently biased to form an opening (111) according to claim 10 after introduction into the tissue,

and/or wherein the shape memory material is resiliently biased to form the grip portion (109) according to claim 11 after introduction into the tissue.

13. The device according to any of the preceding claims, wherein the medical fixture (100) comprises at least two spring-like spiral structures (107) having a common longitudinal axis (106) and being mechanically coupled to each other, wherein at least one of the medical fixtures (100) comprises a fastening member (112) according to claims 9 to 12.